In this disclosure, where a document, an act, and/or an item of knowledge is referred to and/or discussed, then such reference and/or discussion is not an admission that the document, the act, and/or the item of knowledge and/or any combination thereof was at a priority date, publicly available, known to a public, part of common general knowledge, and/or otherwise constitutes any prior art under any applicable statutory provisions; and/or is known to be relevant to any attempt to solve any problem with which this disclosure is concerned with. Further, nothing is disclaimed.
Sometimes, a tube, such as a copper tube or a copper-alloy tube, is unintentionally manufactured with a defect, such as a hole, a weak spot, a dent, a notch, a flaw, a scratch, a depression, a projection, a deformity, or others. In certain cases, the defect renders the tube undesired for use, such as due to the tube being unsafe because of the defect or inoperative because of the defect. As such, the tube is tested, such as randomly, for a presence of the defect.
One way the tube is tested for the defect is via an American Society for Testing and Materials (ASTM) Standard E243, which describes a procedure for an electromagnetic (eddy current) examination of the tube. For example, as illustrated in FIGS. 1 and 2, this examination involves a single-element eddy current test (ECT) probe, which includes a coil of a conductive wire that is excited with an alternating current (AC). During such excitement, the coil produces an alternating magnetic field around itself in a direction ascertained by a right-hand rule. The alternating magnetic field oscillates at a same frequency as the AC passing through the coil. Consequently, when the coil is positioned in a close proximity to a conductive material, such as the tube, a current, such as an eddy current, opposed to the AC in the coil is induced in the conductive material. As such, a variation in an electrical conductivity of the conductive material or a magnetic permeability of the conductive material, along with the presence of the defect cause a change in the current, including a change in a phase of the current and an amplitude of the current. The change in the current is detected by a sensor that senses a change in an impedance of the coil. The change in the impedance of the coil is a sign of the presence of the defect.
Although testing in accordance with the ASTM Standard E243 is useful, there are situations when the presence of the defect is still missed. As such, periodically, the tube is intentionally manufactured with the defect and then tested in accordance with the ASTM Standard E243, in order to ensure that testing in accordance with the ASTM Standard E243 is being correctly conducted. However, this methodology is time-consuming to perform and costly to manage. Additionally, if the tube is lubricated with a lubricant, then testing in accordance with the ASTM Standard E243 becomes more complicated due to an electromagnetic interference between the alternating magnetic field and the lubricant. The electromagnetic interference makes testing in accordance with the ASTM Standard E243 time-consuming to perform and costly to manage. Moreover, if the tube varies in shape, cross-section, size, material, or other tube characteristics, then testing in accordance with the ASTM Standard E243 becomes more complicated because, for each such tube variation, an appropriate coil is needed, which is time-consuming to perform and costly to manage. Accordingly, there is a desire to address at least one of such inefficiencies.